Exoplanetary science is a very active field of astronomy nowadays, with questions still opened such as how planetary systems form and evolve (occurrence, process), why such a diversity of exoplanets is observed (mass, radius, orbital parameters, temperature, composition), and what are the interactions between planets, circumstellar disk and their host star. Several complementary methods are used for the detection of exoplanets. Among these, imaging aims at the direct detection of the light reflected, scattered or emitted by exoplanets and circumstellar disks. This allows their spectral and polarimetric characterization. Such imaging remains challenging because of the large luminosity ratio (1e4-1e10$) and the small angular separation (fraction of an arcsecond) between the star and its environment. Over the past two decades, numerous techniques, including coronagraphy, have been developed to make exoplanet imaging a reality. This review gives a broad overview of the subsystems that make up a coronagraphic instrument for imaging exoplanetary systems. It is especially intended for non-specialists or newcomers in the field. We explain the principle of coronagraphy and propose a formalism to understand their behavior. We discuss the impact of wavefront aberrations on the performance of coronagraphs and how they induce stellar speckles in the scientific image. Finally, we present instrumental and signal processing techniques used for on-sky minimization or a posteriori calibration of these speckles in order to improve the performance of coronagraphs.
{"title":"Imaging exoplanets with coronagraphic instruments","authors":"R. Galicher, J. Mazoyer","doi":"10.5802/crphys.133","DOIUrl":"https://doi.org/10.5802/crphys.133","url":null,"abstract":"Exoplanetary science is a very active field of astronomy nowadays, with questions still opened such as how planetary systems form and evolve (occurrence, process), why such a diversity of exoplanets is observed (mass, radius, orbital parameters, temperature, composition), and what are the interactions between planets, circumstellar disk and their host star. Several complementary methods are used for the detection of exoplanets. Among these, imaging aims at the direct detection of the light reflected, scattered or emitted by exoplanets and circumstellar disks. This allows their spectral and polarimetric characterization. Such imaging remains challenging because of the large luminosity ratio (1e4-1e10$) and the small angular separation (fraction of an arcsecond) between the star and its environment. Over the past two decades, numerous techniques, including coronagraphy, have been developed to make exoplanet imaging a reality. This review gives a broad overview of the subsystems that make up a coronagraphic instrument for imaging exoplanetary systems. It is especially intended for non-specialists or newcomers in the field. We explain the principle of coronagraphy and propose a formalism to understand their behavior. We discuss the impact of wavefront aberrations on the performance of coronagraphs and how they induce stellar speckles in the scientific image. Finally, we present instrumental and signal processing techniques used for on-sky minimization or a posteriori calibration of these speckles in order to improve the performance of coronagraphs.","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43466537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In a 1836 publication on astronomical refractions, Biot (1774–1862) introduced a change of variable, which would become classical, in order to numerically calculate the refraction integral. This change renders well-behaved the integral, in the case when a celestial body is seen on the astronomical horizon. Biot also proves a beautiful theorem, giving the local vertical angular magnification on such horizon. In addition, he comments on various atmospheric models. Published online: 21 February 2023, Issue date: 11 August 2023
{"title":"Le théorème de Biot et le changement de variable de Biot–Auer–Standish : commentaire historique","authors":"L. Dettwiller","doi":"10.5802/crphys.117","DOIUrl":"https://doi.org/10.5802/crphys.117","url":null,"abstract":"In a 1836 publication on astronomical refractions, Biot (1774–1862) introduced a change of variable, which would become classical, in order to numerically calculate the refraction integral. This change renders well-behaved the integral, in the case when a celestial body is seen on the astronomical horizon. Biot also proves a beautiful theorem, giving the local vertical angular magnification on such horizon. In addition, he comments on various atmospheric models. Published online: 21 February 2023, Issue date: 11 August 2023","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41641916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. In his 1758 book, Lambert (1728–1777) established the most compact expression of the refraction integral, and developed it in a power series of sine or tangent of the zenithal distance. He then examined the geodetic consequences of the curvature of the light rays. Mots-clés. Lambert (séries de), Intégrale de réfraction, Coe ffi cient de réfraction, Dépression de l’horizon, Distance de l’horizon
． 在1758年的著作中，兰伯特(1728-1777)建立了最紧凑的折射积分表达式，并将其发展为天顶距离正弦或正切的幂级数。然后他研究了光线曲率对大地测量的影响。Mots-cles。Lambert (ssamries de)、intacimgrale de racry、Coe ffcient de racry、danci.915.com、danci.915.com
{"title":"Les développements de Lambert : commentaire historique","authors":"L. Dettwiller","doi":"10.5802/crphys.116","DOIUrl":"https://doi.org/10.5802/crphys.116","url":null,"abstract":". In his 1758 book, Lambert (1728–1777) established the most compact expression of the refraction integral, and developed it in a power series of sine or tangent of the zenithal distance. He then examined the geodetic consequences of the curvature of the light rays. Mots-clés. Lambert (séries de), Intégrale de réfraction, Coe ffi cient de réfraction, Dépression de l’horizon, Distance de l’horizon","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43943664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Relations among atmospheric structure, refraction, and extinction","authors":"A. T. Young","doi":"10.5802/crphys.125","DOIUrl":"https://doi.org/10.5802/crphys.125","url":null,"abstract":"","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41985954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Résumé. Dans un article primé de 1882, Radau (1835–1911) fait le point sur diverses expressions de la réfraction, dont celle en série entière de la tangente de la distance zénithale apparente. Nous nous focalisons sur l’expression intégrale de ses coe ffi cients, sur l’approximation fondamentale utilisée pour les calculer, et sur l’introduction ultérieure (1906), dans ce but, de multiples familles de hauteurs caractéristiques de l’atmosphère. Nous commentons la divergence, due à l’approximation fondamentale, de la série obtenue dans le cas de l’atmosphère isotherme (donc illimitée). Abstract. In an award-winning 1882 article, Radau (1835–1911) takes stock of various expressions of refraction, including the power series of the tangent of the apparent zenith distance. We focus on the integral expression of its coe ffi cients, on the fundamental approximation used to calculate them, and on the subsequent introduction (1906) for this purpose of multiple families of characteristic heights of the atmosphere. We comment on the divergence, due to the fundamental approximation, of the series obtained in the case of the isothermal atmosphere (therefore unlimited).
{"title":"Les développements de Radau et leur divergence : commentaire historique","authors":"L. Dettwiller","doi":"10.5802/crphys.119","DOIUrl":"https://doi.org/10.5802/crphys.119","url":null,"abstract":"Résumé. Dans un article primé de 1882, Radau (1835–1911) fait le point sur diverses expressions de la réfraction, dont celle en série entière de la tangente de la distance zénithale apparente. Nous nous focalisons sur l’expression intégrale de ses coe ffi cients, sur l’approximation fondamentale utilisée pour les calculer, et sur l’introduction ultérieure (1906), dans ce but, de multiples familles de hauteurs caractéristiques de l’atmosphère. Nous commentons la divergence, due à l’approximation fondamentale, de la série obtenue dans le cas de l’atmosphère isotherme (donc illimitée). Abstract. In an award-winning 1882 article, Radau (1835–1911) takes stock of various expressions of refraction, including the power series of the tangent of the apparent zenith distance. We focus on the integral expression of its coe ffi cients, on the fundamental approximation used to calculate them, and on the subsequent introduction (1906) for this purpose of multiple families of characteristic heights of the atmosphere. We comment on the divergence, due to the fundamental approximation, of the series obtained in the case of the isothermal atmosphere (therefore unlimited).","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43874297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"La discussion par Kummer d’une quadrature sur la réfraction astronomique : commentaire historique","authors":"L. Dettwiller","doi":"10.5802/crphys.118","DOIUrl":"https://doi.org/10.5802/crphys.118","url":null,"abstract":"","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45171992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. The often blurry appearance of astronomical images at a telescope focus is attributed to atmospheric agitation. The study of the light propagation through the turbulent Earth atmosphere has made it possible to understand the existence of optical turbulence resulting from di ff raction phenomena that accompany the refraction of light rays. Optical turbulence is described by parameters (Fried parameter, isoplanetism angle, coherence time, external scale) which characterize the amplitude and the phase of the wave front on the telescope pupil. We deduce the properties of the images (short or long exposure) formed at the telescope focus as well as the description of the e ff ects of turbulence on these images (scintillation, agitation, spreading) and on interferometric observations (piston e ff ect)
{"title":"Les effets optiques de la turbulence atmosphérique dans les images astronomiques","authors":"D. Bonneau","doi":"10.5802/crphys.101","DOIUrl":"https://doi.org/10.5802/crphys.101","url":null,"abstract":". The often blurry appearance of astronomical images at a telescope focus is attributed to atmospheric agitation. The study of the light propagation through the turbulent Earth atmosphere has made it possible to understand the existence of optical turbulence resulting from di ff raction phenomena that accompany the refraction of light rays. Optical turbulence is described by parameters (Fried parameter, isoplanetism angle, coherence time, external scale) which characterize the amplitude and the phase of the wave front on the telescope pupil. We deduce the properties of the images (short or long exposure) formed at the telescope focus as well as the description of the e ff ects of turbulence on these images (scintillation, agitation, spreading) and on interferometric observations (piston e ff ect)","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46789647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Entropy of metallic glasses and the size effect on glass transition","authors":"Y. Champion","doi":"10.5802/crphys.130","DOIUrl":"https://doi.org/10.5802/crphys.130","url":null,"abstract":"","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47126422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. In a 1933 article, Link (1906–1984) shows how to calculate the lunar disc irradiance during a total eclipse,bytakinginaccounttherefractionandextinctionoflightintheEarth’satmosphere,aswellasthelimb darkeningofthe Sun. Hence, he deduces some properties of the terrestrial ozone layer. This article illustrates how Hausdor ff ’s research on the upper atmosphere, based on the study of refraction and photometry, was extended during the first half of the 20th century, before space research emerged.
{"title":"La photométrie des éclipses de Lune, vue par František Link : commentaire historique","authors":"Luc Dettwiller","doi":"10.5802/crphys.120","DOIUrl":"https://doi.org/10.5802/crphys.120","url":null,"abstract":". In a 1933 article, Link (1906–1984) shows how to calculate the lunar disc irradiance during a total eclipse,bytakinginaccounttherefractionandextinctionoflightintheEarth’satmosphere,aswellasthelimb darkeningofthe Sun. Hence, he deduces some properties of the terrestrial ozone layer. This article illustrates how Hausdor ff ’s research on the upper atmosphere, based on the study of refraction and photometry, was extended during the first half of the 20th century, before space research emerged.","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48402344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Some strange things about the mechanical properties of glass","authors":"T. Rouxel","doi":"10.5802/crphys.126","DOIUrl":"https://doi.org/10.5802/crphys.126","url":null,"abstract":"","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46621995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：